Composite closure member

ABSTRACT

A reusable, composite, container closure having a central panel formed of sheet material and a rim formed of molded thermoplastic material.

SUMMARY OF THE INVENTION

This invention relates to reusable closure members of the type used forclosing ends of tubular containers such as cartons or cans.

The particular invention is directed to a composite closure member, ofthe type disclosed in U.S. Pat. No. 3,956,550, comprising a continuous,molded plastic rim and a central panel of sheet material such aspaperboard having a marginal portion bonded to the rim by the materialof which the rim is formed. In view of the fact that the central panelof a composite closure of the type described is formed of relativelythin sheet material, after several applications to a container there maybe a tendency for it to develop unsightly creases or wrinkles.

It is therefore an object of the invention to provide a compositeclosure member of the type described which will resist wrinkling uponcontinual reuse so as to remain attractive.

A more specific object of the invention is to provide, in a closuremember of the type described, a means for controlling the contour of theperipheral or marginal portion of the central panel by providing aplurality of radial flutes or ridges and grooves, the latter of whichare filled in with the material of which the rim is formed.

These and other objects of the invention will be apparent from anexamination of the following description and drawings.

THE DRAWINGS

FIG. 1 is a plan view of a composite closure member embodying featuresof the invention;

FIG. 2 is a vertical section taken on line 2--2 of FIG. 1;

FIG. 3 is a fragmentary, perspective view, partially in vertical sectiontaken through the center of a flute in the panel;

FIG. 4 is a view similar to that of FIG. 3, but taken between twoadjacent flutes; and

FIG. 5 is a fragmentary, vertical section taken on line 5--5 of FIG. 4.

It will be understood that, for purposes of clarity, certain elementsmay have been intentionally omitted from certain views where they arebelieved to be illustrated to better advantage in other views.

THE DESCRIPTION

Referring now to the drawings for a better understanding of theinvention, it will be seen that the composite closure member embodyingfeatures of the invention comprises a continuous rim, indicatedgenerally at R, formed of an injection molded thermoplastic material,and a central panel, indicated generally at P, formed of relatively thinsheet material such as paperboard.

As best seen in FIGS. 2-4, rim R is shown in circular form, although itmay be oval, rectangular or of any other desired shape. Rim R includes alaterally disposed ledge portion or shelf 10 which in the preferredembodiment is inclined downwardly and radially inwardly, although thedirection and angle of the slope may be modified as appropriate for theparticular contour desired for the closure.

Formed integrally with and depending from shelf 10 is an inner bead 12and an outer wall or skirt 14 which, together with the underside ofshelf 10, define a channel for receiving an upper marginal portion ofthe wall of a container body (not shown). If desired, skirt 14 may beprovided with an inwardly projecting retaining shoulder 16.

Also formed integrally with and extending upwardly from shelf 10 is anouter wall or flange 18 which, together with the adjacent upper surfaceof shelf 10, defines a recess 19.

As best seen in FIGS. 1 and 2, central panel P is formed from a blank ofrelatively thin, generally flexible sheet material such as paperboardand includes a center portion 20 and a peripheral or marginal portion 22which is positioned within rim shelf recess 19 and bonded thereto by thematerial of which the rim is formed. In the preferred embodiment,marginal portion 22 is flared outwardly and upwardly from center portion20. As with the case of rim R, the exact angle and/or direction of theslope of flare of panel marginal portion 22 is not essential to theinvention.

In order to prevent the panel from developing unsightly wrinkles orcreases which may develop upon reuse of the closure, in view of thelight weight and flexibility of central panel P, the invention providesa novel construction therefor.

This is accomplished by fluting panel marginal portion 22 to provide aplurality of closely circumferentially spaced, radially extending,alternately disposed ridges 24 and grooves 26.

In the formation of the closure member, central panel P is placed withinan injection mold, so that when the rim R is molded, marginal portion 22of panel P is bonded to rim R by the material of which the rim isformed, with part of the material being received within grooves 26 ofthe panel marginal portion.

When the rim R is molded, the ridges 24 and the grooves 26 are formedinto the periferal edge 22 by the pressure of the resin forcing the edge22 into a fluted contour in the cavity of the mold.

We claim:
 1. In a reusable, composite container closure member, the combination of:(a) a continuous rim formed from an injection molded, thermoplastic material and comprising:(i) a laterally disposed shelf; (ii) a skirt depending from said shelf for engagement with a wall of a container body; (iii) a recess; (b) a central panel, formed from a blank of generally flexible sheet material such as paperboard, and having a fluted marginal portion presenting a plurality of circumferential spaced, radially extending, alternately disposed ridges and grooves; (c) said panel marginal portion being disposed within the recess of said rim and bonded thereto by the material of said rim with part of said material received in the grooves of said marginal portion. 